701 - Chapter 10 Flashcards
What provides assurances that data has not been modified? And what verifies whether #DATA has retained this?
Integrity…hash
What is a string of alpha numeric characters derived from performing a mathematical calculation on data such as a message, patch, or file? And what is special about this?
Hash… it cannot be reversed, engineered to re-create the original #DATA
What is a common hashing algorithm used today?
SHA-3
What ensures that data is only viewable by authorized users? And what are two methods to ensure this?
Confidentiality… encryption and access control
What scramble #DATA to make it un unreadable if intercepted? It normally includes an algorithm and a key.
Encryption
What form of encryption uses the same key to encrypt and decrypt?
Symmetric encryption
What type of cipher encrypts data one bit at a time? And which cipher encrypts’s data and blocks?
Stream…block
What encryption uses a public and private key created as a matched key pair?
Asymmetric encryption
Which encryption requires PKI to issue certificates?
Asymmetric encryption
And how do the private and public key work with asymmetric encryption?
Anything encrypted with the public key can only be decrypted with the matching private key and anything encrypted with the private key can only be decrypted with the matching public key
What provides a level of confidentiality by hiding #DATA within other files?
Steganography
What validates an identity?
Authentication
What prevents a party from successfully disputing having performed an action?
Non-repudiation
What provides authentication, non-reputation, and integrity?
A digital signature
What is one of the main differences between a hash and checksum?
A check sum is typically a small piece of data and is used to quickly verify the integrity of the data and they are not intended to be crypto graphically secure
What is an example of a check sum usage?
A 16 digit credit card, the last digit is a checksum and is used to verify that the first 15 numbers were entered correctly
What is a common hashing algorithm that is discouraged from being used as a cryptographic cash? And in what instances is it still in use today?
Message Digest 5 MD5… To verify the integrity of Files similar to a checksum
What does hash based message authentication code HMAC do that’s a little bit different than the other hashing algorithms?
It hashes using an initial hashing algorithm such as MD5 or SHA – 256, and then, using a secret key known only by the sender and receiver, it performs another hash
In addition to integrity, what does HMAC also provide? And what often uses HMAC?
Authenticity because only the sender and receiver know the secret key… IPSec and TLS
True or false hashing also encrypts the data?
False
Which hash helps solve the problem of an attacker intercepting and modifying the hash and the contents of the message or file? And how/why?
HMAC… through the use of a shared secret known only by the two parties exchanging the data
What hashing algorithm is recommended for password usage and why?
A strong algorithm such as SHA-3 with a salt…adding the salt protects against an attack against known common password hashes
What occurs when the hashing rhythm creates the same hash from different inputs? And which hashing algorithm is highly susceptible to this?
A hash collision…MD5
Which type of password attack attempts to guess the password of an online system?
Online attacks
Which type of password attack attempts to guess the password stored within a downloaded file?
Off-line attacks
As a system admin, how can you discover an online attack?
By reviewing the event log and looking for ID 4625, failed, log attempt and/or 4740, account lockout
What type of attack attempts to avoid the account lockout but the logs will still show a large volume of failed log on attempts, but with a time lapse between each entry?
Spraying attacks
What type of attack uses a listing of words and character combinations? And what protects against this type of attack?
Dictionary…complex passwords
Which type of attack attempts to guess all possible character combinations? And what helps to protect against this type of attack?
Brute force… complex passwords
What attack is when the attacker discovers the hash of the users password and then uses it to log onto the system as the user?
Pass the hash attack
What is an indicator of a pass the hash attack?
Event ID 46224 with a log on process of NTLMSSP and/or an authentication package of NTLM
What do birthday attacks exploit? What is good protection against a birthday attack
Collisions in hashing algorithms… Increasing the number of bits used in the hash to increase the number of possible ashes
What is a rainbow table attack? What prevents against this type of attack?
An attack that uses a rainbow table which is a huge database of possible passwords with pre-computed hashes for each… salting
What is a salt? And what types of attacks do salts protect against?
A set of random data that is added as additional characters to a password before hashing … Rainbow table attacks, brute force, dictionary attacks
What is an advanced technique used to increase the strength of stored passwords by applying a cryptographic stretching algorithm to the salted password?
Key stretching
What are three key stretching techniques? And which type of attacks do they protect against?
Bcrypt, PBKDF2, Argon2… brute force and rainbow table attacks
Between data at rest, data in motion or data in use, which of these is not encrypted? What methods are used to ensure as much confidentiality as possible with this one?
DATA in use… Purging memory of any sensitive data after processing it
What are the two elements for encryption methods?
The algorithm and the key
What type of encryption always uses the same key to encrypt and encrypt the data?
Symmetric encryption
True or false symmetric, encryption algorithms always use the same key?
False these keys are changed very often
Which cipher divides large miles or messages into specific size blocks, 64 bit or 128 bit, and then encrypts each individual block separately? Which cipher encrypt #DATA has a stream of bites or bits rather than dividing it into blocks?
A block cipher… a stream cipher
When is a stream cipher more efficient than a block cipher?
When encrypting data in a continuous stream such as with audio or video
What is the current NIST standard and is a strong symmetric block cipher that encrypt data in 128 192 or 256 bit key sizes? an increase in key size results in what? And what is the block size used?
Advanced encryption standard AES… a stronger key which means stronger protection…128 bit